all repos — h3rald @ 281222c565ae494929772178df83c9b0567b90ba

The sources of https://h3rald.com

content/glyph/book/extending/validators.html

 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
	<head>
<title>Glyph</title>
<meta name="author" content="Fabio Cevasco" />

<meta name="copyright" content="Fabio Cevasco" />
<meta name="generator" content="Glyph v0.4.0 (http://www.h3rald.com/glyph)" />
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>Using Validators - Glyph</title>
		<meta name="author" content="Fabio Cevasco" />
		<meta name="copyright" content="Fabio Cevasco" />
		<meta name="robots" content="all, follow" />
		<meta name="Revisit-After" content="2 Days" />
		<meta name="language" content="en" />
		<meta name="target_country" content="en-us" />
		<meta name="country" content="United States" />
		<meta name="description" content="H3RALD - Fabio Cevasco's Web Site" />
		<meta name="keywords" content="h3rald, fabio cevasco, glyph, technical writing, html, html5, book" />
		<link rel="shortcut icon" href="/favicon.ico" type="image/x-icon" />
		<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
		<meta content="44.388041;9.073248" name="ICBM" />

		<link href="/css/main.css" media="all" rel="stylesheet" type="text/css" />
		<link href="/glyph/book/styles/default.css" rel="stylesheet" type="text/css" />
</head>

	<body>
		<div id="wrapper">
			<a href="http://github.com/h3rald/h3rald"><img style="position: absolute; top: 0; right: 0; border: 0;" src="http://s3.amazonaws.com/github/ribbons/forkme_right_red_aa0000.png" alt="Fork me on GitHub" /></a>
			<div id="header">
				<!--[if lte IE 6]>
				<div id="ie-warning">
					This site is not compatible with Internet Explorer 6 or lower. You should consider using a more modern browser for a better &ndash; and <em>safer</em> &ndash; web experience. [<a href="http://browsehappy.com/browsers/">Read More...</a>]
				</div>
				<![endif]-->
				<!-- HEADER START -->
				<div id="header-container">
					<div id="header-left">
						<h1><span class="logo"></span><a id="logo" href="/" title="H3RALD"></a></h1>
					</div>
					<div id="header-right">
						<ul id="navigation">
							<li><span class="preload nav-archives"></span><a id="nav-archives" href="/archives/" title="ARCHIVES"></a></li>
							<li><span class="preload nav-projects"></span><a id="nav-projects" href="/projects/" title="PROJECTS"></a></li>
							<li><span class="preload nav-about"></span><a id="nav-about" href="/about/" title="ABOUT"></a></li>
							<li><span class="preload nav-other"></span><a id="nav-other" href="/other/" title="OTHER"></a></li>
						</ul>
					</div>
				</div>
			</div>
			<!-- HEADER END -->
			<div class="ribbon">
			</div>
			<!-- MAIN START -->
			<div id="main">
				<!-- CONTAINER START -->
				<div id="container">
					<!-- CONTENT START -->
					<div id="content" class="clearfixstandard">
						<div id="page-links">
							<span><script type="text/javascript" src="http://w.sharethis.com/button/sharethis.js#publisher=6e34d60c-b14e-4c19-9b2f-7c35a9f0ab09&amp;type=website&amp;linkfg=%23a4282d"></script></span>
						</div>

						<h2>Using Validators</h2>
						<hr />
						<div id="content-body">
							<div class="navigation"><a href="/glyph/book/extending/placeholders.html">Using Placeholders &larr;</a><a href="/glyph/book/index.html">Contents</a><a href="/glyph/book/extending/interpreting.html">&rarr; Interpreting Glyph Code</a></div>
								<p>If you need to make sure that a macro is used properly, consider using <a href="http://yardoc.org/docs/h3rald-glyph/Glyph/Macro/Validators">validators</a>. These methods can be used anywhere within the macro code to check whether certain conditions are met or not. Some default validators are provided to check the number of parameters of a macro, and they are actually used in some system macros.</p>
	<p>If you want to create your own validators, you can call the generic <code>validate</code> method which takes the message to display in case of error, a Hash of options and a block containing the validation to perform.</p>
	<div class="box">
<div class="box-title">Validating macro placement</div>
<p>You can, of course, create your own validators to check whether a macro is used directly within another. While this may seem a good idea to enforce constraints into the way documents are created, it has one major drawback: if you define a macro with such validation, you&#8217;re effectively limiting its usage, so for example you won&#8217;t be able to use within snippets or other custom macros.</p>
<p>Suppose, for example, that the <a href="/glyph/book/macros/macros_block.html#m_box"><code>box</code></a> macro is only allowed directly under a <code>section</code> macro. This means that, for example:</p>
<ul>
	<li>the macro cannot be used within <code>chapter</code> or <code>appendix</code> macros.</li>
	<li>the macro cannot be used in snippets</li>
</ul>
<p>Even if you consider all the possibilities within the scope of the default macros provided with Glyph, this could still make the <code>box</code> macro unusable within custom macros.</p>
<p>For the specific cases where a macro does not make sense unless is within another (e.g. the <a href="/glyph/book/macros/macros_core.html#m_eq"><code>eq</code></a> macro), a <code>within</code> validator is used. Note though, that this validator only checks that the macro is used within another, but it is not necessarily its child.</p>

</div>
							<div class="navigation"><a href="/glyph/book/extending/placeholders.html">Using Placeholders &larr;</a><a href="/glyph/book/index.html">Contents</a><a href="/glyph/book/extending/interpreting.html">&rarr; Interpreting Glyph Code</a></div>
						</div>
						<div id="content-footer">
							<div class="share">
								<script type="text/javascript"><!--
									google_ad_client = "pub-2871497824158668";
									/* 728x90, h3rald 8.0 */
									google_ad_slot = "0081634732";
									google_ad_width = 728;
									google_ad_height = 90;
									//-->
									</script>
									<script type="text/javascript"
										src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
										</script>
									</div>
								</div>
							</div>
							<!-- CONTENT END -->
						</div>
						<!-- CONTAINER END -->
					</div>
					<div class="ribbon"></div>
					<!-- MAIN END -->
					<div id="border-bottom">
						<div id="services">
							<div class ="footer-left">
								<div id="backtype">
									<h3><span class="s-opinions preload"></span><a id="s-opinions" href="http://www.backtype.com/h3rald" title="Opinions"></a></h3>
								</div>
							</div>
							<div class ="footer-center">
								<div id="twitter">
									<h3><span class="s-tweets preload"></span><a id="s-tweets" href="http://www.twitter.com/h3rald" title="Tweets"></a></h3>
								</div>
							</div>
							<div class ="footer-right">
								<div id="delicious">
									<h3><span class="s-bookmarks preload"></span><a id="s-bookmarks" href="http://www.delicious.com/h3rald" title="Bookmarks"></a></h3>
								</div>
							</div>
						</div> <!-- SERVICES END -->
					</div>
					<div class="clearfooter"></div>
				</div> <!-- WRAPPER END -->
				<div id="footer">
					<div id="footer-container">
						<div class="footer-div">
							H3RALD Web Site v8.0.0 <em>"xStatic"</em> &mdash; &copy; 2004-2010 <strong>Fabio Cevasco</strong> &mdash; <a class="link" href="http://creativecommons.org/licenses/by-nc-nd/3.0/us/">Some rights reserved</a> | <a href="http://validator.w3.org/check?uri=referer" class="link">XHTML 1.1</a> | <a href="http://jigsaw.w3.org/css-validator/validator?uri=/t_35.html" class="link">CSS 2.1</a>
						</div>
					</div> <!-- END FOOTER CONTAINER-->
				</div> <!-- END FOOTER -->
				<!-- Start of StatCounter Code -->
				<script type="text/javascript">
					var sc_project=6193656; 
					var sc_invisible=1; 
					var sc_security="57f7ee2a"; 
				</script>
				<script type="text/javascript" src="http://www.statcounter.com/counter/counter_xhtml.js"></script>
				<!-- End of StatCounter Code -->
				<script src='http://www.google-analytics.com/ga.js' type='text/javascript'></script>	
				<script src="http://www.google.com/jsapi?key=ABQIAAAA6h3j8Jri5D_da53UPbEbThRlq2n1sm52B5HDRR5tm6o8XM18FhTKn3v155RpPeD0kWnWG81QEhhifQ" type="text/javascript"></script>
				<script src="http://www.google.com/jsapi?key=ABQIAAAA6h3j8Jri5D_da53UPbEbThRlq2n1sm52B5HDRR5tm6o8XM18FhTKn3v155RpPeD0kWnWG81QEhhifQ" type="text/javascript"></script>
					<script src="/js/jquery.js" type="text/javascript"></script> 
					<script src="/js/jquery-timeago.js" type="text/javascript"></script> 
					<script src="/js/jquery-easing.js" type="text/javascript"></script> 
					<script src="/js/jquery-fancybox.js" type="text/javascript"></script> 
					<script src="/js/jquery-toc.js" type="text/javascript"></script> 
					<script src="/js/date.js" type="text/javascript"></script> 
					<script src="/js/feeds.js" type="text/javascript"></script> 
					<script src="/js/search.js" type="text/javascript"></script> 
					<script src="/js/init.js" type="text/javascript"></script> 
				
				
					<script type="text/javascript"> 
						$(document).ready(function() {
								display_opinions(7);
								display_tweets(7);
								display_bookmarks(7);
								});
					</script> 
			</body>
		</html>